Uninflammable celluloid substitute and method of making the same.



I To all whom it-ma concern:

mable Celluloid Substitute Making the Same, of Which the following description is a specification.

HEnBYnnEYr s, or BASELHSWITZERLAIIID,

UNINFLAMMABLE CELLULOIJJ SUBSTITUTE. Am: METHOD or MAKING THE SAME.

1,181,858. No Drawing. Application filed Be it known that I, HENRY DnEYF s, doctor of philosophy, chemist, a citlzen of the Republic of Switzerland, residing at Basel, Switzerland, (whose post-ofiice address is 69' Schiitzenmattstrasse, Basel, Switzerland,) have invented an Uninfiam and Method of The production of a non-inflammable celluloid has been the subject of much research during late years, and either with nitrocellulose in combination .withcamphor or camphor substitutes capable of reducing infiammability, or with acetyl cellulose and c'amphor or camphor substitutes. Although many such substitutes have been proposed, none of them has beencapable ofreplacing camphor, as in general they have not fulfilled the requirements demanded of a camphor substitute. -It has to be borne in mind that for such a substitute in the celluloid manufacture, not only its qualitative character has to be examined, but the relative proportions also play a'great'part, for any other substitute requires graduation in the quantities to be. employed, just as camphor does,

brittle after some time, or

' process for "inter die and the value judged from which it can be seen whether the resulting material is brittle directly, or only becomes is too soft or pos sesses any other defects. The specification of German Patent No. 145,106 describes a process for the production of celluloid-like substances in which" phenol is 'used as a solvent. Nevertheless only elastic or horn-likeproducts' are obtained according to that process; moreover the process is hardly capable ofpractical-employment o-wing to the disagreeable odor, and moreover the production of a celluloid substitute would be impossible according to the working indicated inthe patent specification.

;In specification of the production of celluloidlikezsubstances is described, using tetra- I fl 'chlorethane. The production of a real celluloid substitute however, requires that the same shall be capable of being worked upon the same "machines as those employed ,for

ordinary celluloid, and in particular cal.-.

enders or rollers and presses. Especlally Specification of Letters Patent.

of a substitute can only bethe finished celluloid, from.

and inspection of the Patented May 2, 1916.

October 2, 1911, Serial No. 652,444.- Renewed December 11, 1915. Serial the rollers are necessary in order to produce various designs or patterns, such as tortoiseshell, etc.v If one Worked according to this patentspecification, using acetyl celluloses obtained according to the German patent specifications therein mentioned, e.- 9.,

163,316; 159,524, etc., one would not-obtain a celluloid substitute' One reason for this is that the said acetyl celluloses are diificultly soluble, but even an excess of'solvent would not overcome the difliculty, as one would then only obtain stickymasses incapable of being worked on the machines,

and which on prolonged drying on calender rollers and evaporation of the'solvent would return to this original condition How important is the part played by the degree of solubility of the acetyl cellulose employed, is shown by the fact that there is also known a process wherein (owingto the too small solubility of the cellulose esters) these acetates are to foacetates and phosphoacetates, the solvent capacity of which for the phosphoric esters of phenols, naphthols, cresols, acetins and others is said to be'considerably greater andthe formation of celluloid to be therefore possible. Moreover in-the specification of German Patent 188,542 the mass is taken direct to presses for the formation of objects or blocks, etc. But the rollers are essential for the production of designs, and moreover they allow of further working up, mass. It is altogether to work up on rollers the masses obtained from acetyl cellulose according to the said patent specification, as the same would simply break and crumble impossible however,

be replaced'by so-oalled sulas the solvent evaporates, insteadof blend h ing under the geneous coherent plastic masses, becoming transparent, WhlCll w ll form v scous. sheets or foil-s and can easily becut with a knife.

of designs or patterns byp the introduction of dissolved or undissolved German Patent 188,5 l2v The production coloring matters or fillers, isentirely impossible, and apart from this fact the material' is brittle, more or less opaque and calerglering action into homospottedwith white. These are all products soluble it istrue, in tetrachlorethane, but

which are nevertheless precipitated from their solutions therein, upon the addition of alcohol; even the product of German Patent15 9,524 which is more easily soluble in tetrachlorethane will bear only a very little alcohol and cannot be used for the production of celluloid, especially on account of its too small solubility. Further it has also been incorrectly assumed that the rapidity of evaporation of the solvents used, as for instance acetone, is the cause of the substance belng j brittle, owing to the material drying too quickly. It has been found in the present process that the brittleness is due inter alz'a to the character of the acetyl celluloses employed, and in particular, to their capacity for dissolving in tetrachlorethane being much too small; evenzif an excess of tetrachlorethane is used for solutlon, thls excess 1s evaporated again in the working up of the product and the mass again becomes opaque and crumbly and brittle, so that it is impossible to work it on rollers. Moreover it is not possible in accordance with the aforesaid assumption to obtain a useful product, andthis apart from the fact that the camphor added allows the infiammability to persist. Besides the important part played by the quality of the acetyl celluloses employed, importance also attaches to the rela tive proportions of tetrachlorethane and alcohol or its substitutes; .for if too much alcohol is used, it acts as a precipitant and the formation of celluloid is impossible, whereas with little alcohol the quantity of tetrachlorethane employed must be preferably increased.

I have found a process which allows of the employment of tetrachlorethane for the production of a real celluloid substitute,

having all the desirable properties of or-.

dinary celluloid. The process enables the f cellulose acetates or cellulose esters to be worked on the same machines as ordinary celluloid and allows of producing designs,

i barium compounds, etc. The new process. depends onthe quality ofthecellulose acepatterns or-colorings in the usual manner for example withdyestufl's soluble inalcohol or diluted alcohol, or with filling mate- I rials such as asbestos in powder, or mineral substances such as bronze, zinc white,

tates employed and to some extent on the quantity of the substance to be used, such as tetrachlorethane and alcohol orthe substitutes of the latter, both among themselvesand relatively to the particular acetyl celluloses or other cellulose esters used. It has been found'in particular that for the trated solutions,- are especially suitable.

Some of them are capable ofgivin solu- 1 tions of up to 50 per cent. and more 0 acetocellulose in a-m1xture pf about equal volcooling they. solidify again into more or less soft to hard transparent masses, which can be worked. up in an analogous manner to ordinary celluloid; and these solutions possess the advanta' es over ordinary celluloid that they 08.11%)8 cast and molded direct into objects of. all kinds. quantity of the solvents employed, as tetrachlorethaneand alcohol or its substitutes, should not on the average exceed together more than about to 100 per cent. of the" cellulose ester used. According as it is desired to make a harder or a softer celluloid substitute, the proportions can be reduced or increased and oils, such as castor oil or the like may be added if desired. The production of celluloid from cellulose esters characterized by their solubility is however not in every case-dependent upon the employment of alcohol or the substitutes of the latter, as it has been found that these cellulose esters can also be used without alcohol although it is true with certain disadvantages. Inthis case, however, it has been found that to provide for the working of the mass, it is preferable to use about 100 to 150 per cent. of tetrachlorethane, relatively to the weight of acetyl cellulose instead of for example only 50 er cent., in.

The total order to efi'ect the melting an uniting of the mass and to enable the same to be excess of solvent, and the quality of the re-v sulting celluloid is detrimentally affected and the latter rendered useless for many purposes. The success of .the present process depends upon the employment of acetyl celluloses or'cellulose esters referred to possessing the above described properties and also upon the proportions of the added substances among themselves and also together in' relation to the. weight of the cellulose esters employed. It has furtherbeen found that the chlorin derivatives of ethylene and ethane allied to tetrachlorethanee. g; pentachlorethane, dichlorethylene, and trichlorethylene, although chemically they are very closely related to each other'and to tetrachlorethane and although they could ardly be expected to show a difierent behavior relatively to cellulose esters, do

nevertheless show individually and in mixtures of some or all of them a great difi'erence in their behavior "toward acetyl celluloses. vPentachlorethane has already been used with the employment of a solvent such as chloroform, in which the acetyl cellulose is first dissolved, in order to produce films therefrom. The subject of the present invention, however, represents inter alia the very employment of the cellulose acetates acetone, for the manufacture of films,

threads and sheets. But according to the aforesaid process'it is only possible'to obtain solutions for celluloid, and the propor acetates are employed.

tions employed are so great that working on the machines usual for celluloid is not possible; only sticky and liquid masses 'would be-obtained. A real substitute that can be worked on the same machines is impossible with said process, as is alsothe coloring with organic and mineralfcoloring matters, and the largely excessive quantities of solvents used are employed useless way. Moreover in said process allcellulose chlorethane it has also been found that only the acetyl 'celluloses giving concentrated solutions in alcohol-tetrachlorethane can be employed, and on the other hand the proportions of the solvents employed (alcohol and pentachlorethane), both in relation to each other and in relation to the acetyl cel-' luloses, are of particular importance, for if for example too much alcohol is added relatively-to the pentachlorethane, it acts as a according as a harder or softer: celluloid is precipitating agent sothat the formation of celluloid is impossible. It has further been found that for the production of a good celluloid substitute, it is of advantage to employ on an average 80 to 100 per cent. of a mixture of pentachlorethane and alcohol or its substitutes, relatively to the weight of' the cellulose acetate employed but these limits may be departed from to a certain extent required. a Y

In using pentachlorethane it has been found preferable to work with a mixture of equal volumes of pentachlorethane and alco- I hol; it is thus possible and particularly by heating, to produce solutions containing up to 50 per cent. and more of cellulose acetates and which can be worked upon the ordinary,

- the possibiltiy of Just as withtetra celluloid machines. A two-fold technical advantage is thus obtained; on the one hand producing a useful celluloid substitute by limiting the total quantities of alcohol and pentachlorethane employed, and on the other hand the restricted quantity of solvents considerably reduces the cost price of the celluloid. It has. further been found that, while tetrachlorethane which of itself and without addition of alcohol or. substitutes thereof, is capable of forming a celluloid substitute with the acetyl \celluloses very soluble in mixtures of tetrachlorethane and alcohol, pentachlorethane is incapable of itself of forming plastic masses with these acetyl celluloses. If for example the acetocelluloses are treated with pentachlorethane in the same manner as with tetrachlorethane, the acetyl cellulose remains indifferent, even when heated and stirred.

' The surprising fact has been discovered,

however, that if tetrachlorethane is added to pentachlorethane, for example in equal volumes, or more or according to circumstances, the pentachlore thane is capable of forming a celluloid substitute even although less advantageously without addition of alcohol or its substitutes. The same result is obtained by employing pentiachloreth ane mixed with methyl acetanilid orother camphor substitutes. Moreover it has been found that trichlorethylene, which of itself has no dissolving capacity for the particular acetyl celluloses, nevertheless in admixture with p'entachlorethane and with tetrachlorethane is capable of forming celluloid masses with acetyl cellulose, and especially in combination with alcohol or its substitutes; This latter fact is in contradiction with the British Patent 16,932 of 1910 and French Patent 418,309 which state that trichlorethylene neither alone nor in combinationwith alcohol has any dissolving capacityfor acetates of cellulose, for it has been found in the present invention that the cellulose acetates referred to which give concentrated solutions in alcohol tetrachlorethane give concentrated solutions in a hot mixture of trichlorethylene and alcohol (for example in a mixture of equal parts by volume 'of trichlorethylene and alcohol) which solutions set on cooling. It has also been found that dichlorethylene in combination with ZZher chlorin derivatives'of acetylene, such pentaand tetra-chlorethane, with or less of the one or the other without alcohol show an analogous behavior with cellulose acetates; the only difference is, as already known, that dichlorethylene of itself has a certain dissolving capacity for certain cellulose acetates. It has also been found that the results obtained according to the present invention are also quite different fromthose of the process of French Patents 412,797 and 419,530, and English Patents 1441 of 1910 and 12,979 .of 1909 which state,

that it had only previously been possible to produce thin coatings'with acetyl cellulose.

and that the production of celluloid is only possible by employing alcohol-benzol. In the present invention it has been found that the result depends only on the quality or character of the cellulose acetates orcellulose esters employed and the qualitative and quantitative selection of the solvents and so- 1 called additions inter s0, and in relation to the cellulose esters employed. I have found that only agents should be employed which aforesaid processes (the French and English patents above referred to) are incorrect is shown by the following: If for example benzene is taken as the volatile agent or alone as the solvent, andone adds the there employed camphor substitutes, the acetyl cellulose remains almost indiflerent even onheating, as the benzene in combination with the camphor substitutes, acts as'a precipitating agent, or as a solubility reducing agent. If on the other hand one takes for example a mixture of equal parts of alcohol and benzene, or petroleum spirit instead of benzene, this mixture even with additions of camphor substitutes, acts as a precipitating agent. The acetyl cellulose remains indifferent, and on the other hand become so soaked with this precipitating agent combined with the added camphor substitute, that the removal of the -mixture is extremely diflicult The result is the same when other volatile liquids are employed, as for instance carbon disulfid, etc. In the present process therefore, the additions of the volatile liquids in these aforesaid processes and the special preparatory treatments of the cellulose acetates connected with the same are not necessary; consequently the new process presents a technical advantage as compared therewith apart from the further advantages of the present invention.

The present process is illustrated by the following examples;

1 Example'lz 80 kilos of cellulose acetate, easily soluble in alcohol-tetrachlorethane, are mixed with about 40 liters of alcohol and 40 kilos of tetrachlorethane and kneaded to a sufiicient extent in a malaxator, preferably while warm; the mass becomes homogeneous and clear. It is then worked up on rollers and in presses, and the resulting block iscut for exampleinto plates or sheets of the desired thickness, which can further be dried"- and dressed or polished according to requirements. To the abovemixture there'may be added at thebeginning, or later, such substances as-castor oil, or mineral or organic colormg matters, or filling substances according to the use in view. If for example it is intended to produce an imitation tortoise shell the mass is divided into two or coloring it is mixed with the other uncolored part by suitable working upon rollers.

In this example 5 kilos of methyl acetanilid,

or other suitable camphor substitute may be added. The 40 kilos "of tetrachlorethane may be replaced by 40 kilos of a mixture of equal parts of tetra-,andpenta-chlorethane.

Example 2: 20 kilos of cellulose acetate,

easily soluble in alcohol-tetrachlorethane are mixed with 20 liters of alcohol and 32 I kilos of tetrachlorethane and further worked up as in the preceding 'example. The material is distinguished by particular softness.

In these examples the proportions of the substances used may both relatively to each other and to, the cellulose acetate referred to and the constituents of the dissolving mixtures, can likewise be varied. The masses obtained in these examples instead of being further worked up on the usual celluloid machines, may be cast in molds directly or after addition of filling materials, oils, and so forth and films or other objects of all kinds may be made from them.

The term alcohol as used in the appended claims is intended to cover the use of. alcohol substitutes.

What I claim is: 0 3 1. In a process of making a celluloid sub-.

stitute, the step which comprises dissolving,-

in .a mixture comprising alcohol and a chlorinated hydrocarbon, a cellulose ester which .is readily soluble therein, in proportions, to form a solution containing not less than 29%.of said ester.

2. In a process of making a. celluloid subbe varied Y somewhat,

stitut'e, the step which comprises dissolving, in a mixture comprising alcohol and a chlorinated hydrocarbon, a cellulose acetate which is readily soluble therein, in proportions to form a solution containing not less than 29% of said acetate.

3. In a process of making-a celluloid sub-v stitute, the step which comprises dissolving,

chlorethane, a cellulose ester which is readily soluble therein, in proportions to .in a mixture comprising alcohol and tetra-- i wumhmllllf 111' a mixture comprising alcohol and a chlorinated hydrocarbon, a cellulose ester which is readily soluble therein, in proportions to form a solution'containmg not less than 29 of said ester, together with a suitable proportion of an oil. a

(i. In the manufacture of a celluloid sube stitute, the process which comprises dissolving, in a mixture comprising alcohol and a chlorinated hydrocarbon, a cellulose ester which is readily soluble therein, in proportions to form a solution containing not less than 29% of said ester, and adding thereto suitable proportions of an oil and a filling material.

T. In the manufacture of a celluloid substitute, the process which comprises dissolving, in a mixture con'iprising alcohol and a chlorinated hydrocarbon, a I cellulose ester which is readily soluble therein, and in adding thereto suitable proportions of an oil, a filling material and a coloring material;

8. In a process of making a celluloid substitute, the step which comprises dissolving in a mixture comprising alcohol and a plurality of chlorinated hydrocarbons, a cellulose ester which is readily soluble therein, in proportions to form a solution containing not less than 29% of said ester. 7

9. In a process of making a celluloid substitute, the step which comprises dissolving in a mixture comprising alcohol and tetrachlorethane and another chlorinated hydrocarbon, a cellulose ester which is readily soluble therein, in proportions to form a solution containing not less than 29% of said ester.

10. In aprocess of making a celluloid substitute, the step which comprises dissolving in a mixture comprising alcohol, tetrachlorethane and entachlorethane, a cellulose ester whichis .e'adily soluble therein, in proportions to form a solution containing not less than 29% of said ester.

11. A process of making a celluloid substitute, which comprises dissolving in a mixture comprising alcohol, tetrachlorethane, and pei'itachlorethane, a cellulose acetate which is readily soluble therein, in proportions to form a solution containing about of said acetate, and adding suitable proportions of castor oil, filling and'color ing bodies, and thereafter separating said solvents by evaporation.

12. A celluloid substitute having a cellulose ester readily soluble in a mixture of alcohol and tetrachlorethane as a base, said product being relatively noninflammable, nonbrittle, transparent, and capable of being worked up in the same manner as celluloid.

13. A celluloid substitute having cellulose acetate soluble in a mixture of alcohol and tetrachlorethane as a base,'containing an oil, said product being relatively nonintiammable, nonbrittle, transparent, and capable of being worked up in the same manner as celluloid.

1- A celluloid substitute having cellulose acetate soluble in a mixture of alcohol and tetrachlorethane as a base, containing coloring material and an oil, said product being relatively noninfialnmable, nonbrittle, transparent, and capable of being worked up in the same manner as celluloid.

In testimony whereof I have hereunto set my .hand in the presence of two subscribing witnesses.

Paris, dated this 20th day of September a 1911.

DR. HENRY DREY'FUS'.

Witnesses:

H. C. CoXE,

UAMILLE DREYFUS. 

